Field of the Invention
The present invention relates to a vehicle wheel axle assembly, particularly including aspects that facilitate the connection between axle of a vehicle wheel and the frame to which the vehicle wheel is mounted. More specifically, the present invention relates to a vehicle wheel axle assembly that includes a control shaft that may be axially shuttled such that both ends of the control shaft are simultaneously engaged to the frame at a first axial position and simultaneously disengaged or released from the frame at a second axial position. The present invention is particularly applicable to a bicycle wheel axle assembly that facilitates the connection between axle of a bicycle wheel and the frame of a bicycle.
Discussion of Prior Art
Heretofore, the prior art mechanisms for the attachment and connection of bicycle wheels to the bicycle frame and/or fork has included two basic categories: the quick release skewer and the through-axle.
It is highly desirable to be able to install and uninstall the bicycle wheel to the frame very quickly and easily. Particularly in bicycle racing conditions, when every second counts, the ability to quickly swap out wheels (in the case of a flat tire, for instance) is critical. Reducing the time required to install and uninstall the wheel may result in the margin of difference between winning and losing the race.
It is also highly desirable that the system for wheel attachment be simple and intuitive to operate. The user must be able to learn its operation with a minimum of instruction. Further, this operation should not be overly complex or require a significant level of skill on the part of the operator. Still further, this system should minimize the number of separable parts that the operator must keep track of. Yet further, it is important that the system provide a robust and solid connection between the wheel and the frame (and/or fork) that also serves to create a stiff and robust connection between the dropouts of the frame.
The prior-art quick release skewer wheel attachment system utilizes a thin skewer shaft and this system relies on a certain level of elastic stretch of this shaft in order to function properly. The problem is that this thin shaft also serves to compromise the stiffness and robustness of this wheel attachment.
This system also requires the use of a cam lever and adjusting nut, where the operator must test the lever tension for proper lever tension “feel”, then readjust the nut and try again. Even the most experienced operator commonly goes through this iterative adjustment procedure 3-4 times before being satisfied with the wheel attachment. Further, there is no reliable indication as to what constitutes the proper lever tension “feel”. For less experienced operator, this operation is deemed quite complex not at all intuitive. And the level of judgment and interpretation required of the operator regarding the proper lever tension “feel” requires more experience than most users have. As such, the quick release skewer system requires a high degree of operator training, and even then, the reliability that this connection has been achieved properly is quite low. In fact, the quick release skewer system has resulted in numerous cases where the wheel has inadvertently become separated from the bicycle, resulting in serious injury and resulting in numerous lawsuits.
With the advent of mountain bikes, and with the desire to have a more robust and stiff wheel attachment system, the through axle has been utilized as a heavier-duty wheel attachment system. This system is similar to that used on motorcycles and has a separate axle element that is passed axially through the dropouts of the frame and through the axle sleeve of the wheel. This means that this separate axle component must be axially withdrawn over a very long distance in order to separate the wheel from the bicycle and must be axially inserted over the same distance for wheel installation. The result is that the through-axle system requires an excessive amount of time to achieve the attachment and removal of the wheel to/from the dropouts of the frame. Further, this axle is now an additional separate component that the operator must keep track of when the wheel is removed from the dropouts. For this reason, the through-axle system is commonly used only in heavier-duty mountain bike applications.